Heaters For Greenhouse

A greenhouse heater is the key to extending your growing season and protecting your plants when temperatures drop. Whether you're growing vegetables, tropical plants, or overwintering sensitive flowers, maintaining a stable climate is essential. Cold snaps can quickly undo months of progress – but with the right heating system, your greenhouse stays productive through autumn, winter, and early spring.

Heaters come in all shapes and sizes, from compact electric models to more powerful fan-assisted units. Some even include integrated thermostats that let you set a target temperature and maintain it automatically. This not only protects your plants but also saves energy and reduces costs.

Even a few degrees of extra warmth can make a huge difference – keeping roots healthy, preventing frost damage, and promoting stronger, more consistent growth. With a reliable greenhouse heater, you’re no longer at the mercy of the weather.

Choosing the Right Greenhouse Heater for Your Needs

Not all greenhouses – or growers – are the same. That’s why it’s important to match your greenhouse heater to your space, climate, and plant types. A small plastic walk-in greenhouse may only need a low-watt electric heater, while a larger glass or polycarbonate structure could benefit from a thermostat-controlled fan heater.

First, consider your greenhouse size (in m² or m³). The bigger the space, the more power you’ll need to keep temperatures stable. Second, think about airflow – heaters with built-in fans help distribute warmth more evenly. Third, decide between manual or automatic temperature control – digital thermostats can be more efficient and convenient.

Also take into account the local climate: in milder areas, frost protection might be enough, while in colder regions you’ll need consistent heat throughout the night. Finally, consider energy efficiency and placement – heaters work best when positioned near air intakes or cold zones, like the far end of the structure.

Choosing the right heater isn’t just about power – it’s about balance, efficiency, and providing the exact conditions your plants need to thrive.

Types of Greenhouse Heaters: Electric, Solar & Decorative Bioethanol

There are several effective options when it comes to heating your greenhouse – each suited to different needs, climates, and purposes.

Electric greenhouse heaters are by far the most popular. They’re clean, efficient, and often come with built-in thermostats and integrated fans for even heat distribution. These plug-and-play units are ideal for both small walk-in plastic greenhouses and larger glass or polycarbonate structures. Their ease of use and low maintenance make them the preferred choice for most gardeners.

Solar greenhouse heaters are an increasingly popular eco-friendly alternative. While they typically can’t heat a space entirely on their own, they offer great support by storing warmth during daylight hours (often via thermal mass) and releasing it slowly at night. Some solar-powered models use small fans to help circulate air and can be paired with insulation to maximise their effectiveness.

If your greenhouse is also used for relaxation or as an orangery, many choose to install a bioethanol fireplace as a decorative supplement. While not a substitute for active plant heating, a biofire adds a cozy, ambient warmth and creates a beautiful atmosphere for reading, tea time, or enjoying winter sun – all without smoke, soot, or a chimney.

Each heating method serves its own role – from efficient plant care to enhancing the overall experience of your greenhouse space.

Greenhouse Heater Placement and Usage Tips

To get the most out of your greenhouse heater, proper placement is essential. Heat rises, so positioning your heater low to the ground ensures warmth reaches plant roots where it matters most. Avoid placing heaters directly under delicate foliage to prevent scorching.

For optimal efficiency, position the heater at the opposite end of your ventilation or airflow system. This encourages circulation and helps distribute warm air evenly. Many gardeners use small oscillating fans alongside heaters to keep air moving and prevent cold spots or condensation buildup.

It’s also important to insulate your greenhouse if possible. Add bubble wrap insulation to walls or roof panels to reduce heat loss. Seal drafts around doors and windows, and consider using thermal curtains overnight. Always follow safety instructions and ensure the heater is rated for greenhouse use – especially in damp or unheated spaces. Avoid extension cords unless they’re waterproof and outdoor-rated.

A heater that’s used wisely doesn’t just protect your plants – it also saves energy and money in the long run by maintaining a stable climate with less power.

Efficient Heating = Healthy Plants and Lower Costs

Using a greenhouse heater effectively is not just about warmth – it’s about optimising plant health while controlling your energy usage. When your greenhouse maintains consistent, moderate temperatures, plants grow more predictably, resist disease better, and yield greater harvests.

Heaters with thermostats or timers allow you to avoid overheating and cut costs by only heating when needed. Some digital models even let you set day/night temperature cycles, replicating natural conditions for more vigorous growth. Combined with good ventilation and insulation, even a small heater can keep your greenhouse productive all year long.

It’s also worth considering solar panels or renewable energy sources if you’re heating a large greenhouse regularly. This allows you to grow sustainably while reducing your reliance on grid electricity. Whether you’re protecting your first tray of seedlings or managing a year-round grow space, the right heating setup brings peace of mind, healthier plants, and better yields – without breaking the bank.